Showing papers in "Vehicle System Dynamics in 2012"
TL;DR: In this paper, the authors combine electric drive and in-wheel-motor (IWM) to achieve good vehicle dynamics and a roomy interior, and the responsiveness of IWM raises the performance of the dynamic control to an even higher level.
Abstract: The in-wheel-motor (IWM) will be the most important key technology in the near future to be used by electric vehicles (including fuel cell vehicles). In the past 100 years of the internal combustion engine, several kinds of vehicle packages have been developed, for example, front-engine front-wheel drive, front-engine rear-wheel drive, mid-engine rear-wheel drive, and rear-engine rear-wheel drive. However, a conclusive solution for the best package has not been found. Combining electric drive and IWM enables both good vehicle dynamics and a roomy interior. In addition, the responsiveness of IWM raises the performance of the dynamic control to an even higher level.
173 citations
TL;DR: In this paper, a vehicle dynamics controller is composed of three modules, i.e. motion following control, control allocation and vehicle state estimation, aiming at improving vehicle stability under critical driving conditions.
Abstract: This paper focuses on the vehicle dynamic control system for a four in-wheel motor drive electric vehicle, aiming at improving vehicle stability under critical driving conditions. The vehicle dynamics controller is composed of three modules, i.e. motion following control, control allocation and vehicle state estimation. Considering the strong nonlinearity of the tyres under critical driving conditions, the yaw motion of the vehicle is regulated by gain scheduling control based on the linear quadratic regulator theory. The feed-forward and feedback gains of the controller are updated in real-time by online estimation of the tyre cornering stiffness, so as to ensure the control robustness against environmental disturbances as well as parameter uncertainty. The control allocation module allocates the calculated generalised force requirements to each in-wheel motor based on quadratic programming theory while taking the tyre longitudinal/lateral force coupling characteristic into consideration. Simulations under a variety of driving conditions are carried out to verify the control algorithm. Simulation results indicate that the proposed vehicle stability controller can effectively stabilise the vehicle motion under critical driving conditions.
131 citations
TL;DR: In this paper, the authors investigated the possibility of improving the performance of railway vehicle suspensions by incorporating a newly developed mechanical device known as the inerter, which improved the lateral and vertical ride comfort, as well as lateral body movement when curving.
Abstract: This paper investigates the possibility of improving the performance of railway vehicle suspensions by incorporating a newly developed mechanical device known as the inerter A comparative study of several low-complexity passive suspension layouts is made Improved performance for the lateral and vertical ride comfort, as well as lateral body movement when curving are demonstrated in comparison with the conventional suspension layout The constraints imposed are to maintain the same level of other performance metrics The calculations and optimisations are based on linearised plan-view and side-view high-speed train mathematical models
121 citations
TL;DR: In this article, a detailed investigation conducted into the mechanism of the polygonal wear of metro train wheels through extensive experiments conducted at the sites is presented, including model tests of a vehicle and its parts and the tracks, the dynamic behaviour test of the vehicle in operation and the observation test of polygonale wear development of the wheels.
Abstract: This paper presents a detailed investigation conducted into the mechanism of the polygonal wear of metro train wheels through extensive experiments conducted at the sites. The purpose of the experimental investigation is to determine from where the resonant frequency that causes the polygonal wear of the metro train wheels originates. The experiments include the model tests of a vehicle and its parts and the tracks, the dynamic behaviour test of the vehicle in operation and the observation test of the polygonal wear development of the wheels. The tracks tested include the viaducts and the tunnel tracks. The structure model tests show that the average passing frequency of a polygonal wheel is approximately close to the first bending resonant frequency of the wheelset that is found by the wheelset model test and verified by the finite element analysis of the wheelset. Also, the dynamic behaviour test of the vehicle in operation indicates the main frequencies of the vertical acceleration vibration of the axl...
112 citations
TL;DR: In this paper, the authors used the vehicle's center of percussion (COP) to design feedforward and feedback steering for an autonomous racing controller, which is shown to remain stable even when the rear tires are highly saturated.
Abstract: Understanding how a race car driver controls a vehicle at its friction limits can provide insights into the development of vehicle safety systems. In this paper, a race car driver's behaviour inspires the design of an autonomous racing controller. The resulting controller uses the vehicle's centre of percussion (COP) to design feedforward and feedback steering. At the COP, the effects of rotation and translation from the rear tire force cancel each other out; consequently, the feedforward steering command is robust to the disturbances from the rear tire force. Using the COP also simplifies the equations of motion, as the vehicle's lateral motion is decoupled from the vehicle's yaw motion and highlights the challenge of controlling a vehicle when the rear tires are highly saturated. The resulting dynamics can be controlled with a linear state feedback based on a lane-keeping system with additional yaw damping. Utilising Lyapunov theory, the closed-loop system is shown to remain stable even when the rear tires are highly saturated. The experimental results demonstrate that an autonomous vehicle can operate at its limits while maintaining a minimal lateral error.
102 citations
TL;DR: In this paper, a review of the integration of new electrified powertrains with the vehicle dynamics and control systems is presented, which can be discussed in terms of three generic vehicle motions, namely roll-plane, pitch-plane and yaw-plane.
Abstract: The background to the development of so-called green or low-carbon vehicles continues to be relentlessly reviewed throughout the literature. Research and development (R&D) on novel powertrains - often based on electric or hybrid technology - has been dominating automotive engineering around the world for the first two decades of the twenty-first century. Inevitably, most of the R&D has focused on powertrain technology and energy management challenges. However, as new powertrains have started to become commercially available, their effects on other aspects of vehicle performance have become increasingly important. This article focuses on the review of the integration of new electrified powertrains with the vehicle dynamics and control systems. The integration effects can be discussed in terms of three generic aspects of vehicle motions, namely roll-plane, pitch-plane and yaw-plane, which however are strongly coupled. The topic on regenerative suspension is further discussed. It quickly becomes clear that this integration poses some interesting future engineering challenges to maintain currently accepted levels of ride, handling and stability performance.
101 citations
TL;DR: In this paper, the anti-lock braking system (ABS) is designed for in-wheel electric vehicles, which is composed of a tyre slip controller, a wheel torque allocator and a braking supervisor.
Abstract: Among the many opportunities offered by electric vehicles (EVs), the design of power trains based on in-wheel electric motors represents, from the vehicle dynamics point of view, a very attractive prospect, mainly due to the torque-vectoring capabilities. However, this distributed propulsion also poses some practical challenges, owing to the constraints arising from motor installation in a confined space, to the increased unsprung mass weight and to the integration of the electric motor with the friction brakes. This last issue is the main theme of this work, which, in particular, focuses on the design of the anti-lock braking system (ABS). The proposed structure for the ABS is composed of a tyre slip controller, a wheel torque allocator and a braking supervisor. To address the slip regulation problem, an adaptive controller is devised, offering robustness to uncertainties in the tyre–road friction and featuring a gain-scheduling mechanism based on the vehicle velocity. Further, an optimisation framework ...
100 citations
TL;DR: In this article, polynomial chaos approaches that explicitly consider parametric uncertainty during modelling of vehicle dynamics are presented, and experimental results compared with the simulation results performed on ANVEL (a vehicle simulator) indicate that the method can be used to predict vehicle motion in realistic scenarios.
Abstract: The ability of ground vehicles to quickly and accurately analyse their dynamic response to a given input is critical to their safety and efficient autonomous operation. In field conditions, significant uncertainty is associated with terrain and/or vehicle parameter estimates, and this uncertainty must be considered in the analysis of vehicle motion dynamics. Here, polynomial chaos approaches that explicitly consider parametric uncertainty during modelling of vehicle dynamics are presented. They are shown to be computationally more efficient than the standard Monte Carlo scheme, and experimental results compared with the simulation results performed on ANVEL (a vehicle simulator) indicate that the method can be utilised for efficient and accurate prediction of vehicle motion in realistic scenarios.
98 citations
TL;DR: In this article, the use of inerters to improve the stability and performance of a full-train system is discussed, and the benefits of iners are investigated by the critical speed, settling time and passenger comfort.
Abstract: This paper discusses the use of inerters to improve the stability and performance of a full-train system. First, we construct a 28 degree-of-freedom train model in AutoSim, and obtain a linearised model for analysis in Matlab. Then, the benefits of inerters are investigated by the critical speed, settling time and passenger comfort. In addition, we apply a new mechatronic network for further performance improvement, and synthesise the optimal electrical circuit for experimental verification. From the results, inerters are shown to be effective in improving the stability and performance of train systems.
97 citations
TL;DR: In this article, three road profile models are proposed: a homogenous Laplace moving average process, a non-homogeneous Laplace process and a hybrid model that combines Gaussian and Laplace modelling.
Abstract: This study focuses on the statistical description and analysis of road surface irregularities that are essential for heavy-vehicle fatigue assessment. Three new road profile models are proposed: a homogenous Laplace moving average process, a non-homogenous Laplace process and a hybrid model that combines Gaussian and Laplace modelling. These are compared with the classical homogenous Gaussian process as well as with the non-homogenous Gaussian model that represents the road surface as a homogenous Gaussian process with Motor Industry Research Association spectrum enhanced by randomly placed and shaped irregularities. The five models are fitted to eight measured road surfaces and their accuracy and efficiency are discussed.
96 citations
TL;DR: In this article, the authors present four methods to estimate the friction coefficient based on four different excitation conditions: medium lateral, large lateral, small longitudinal, and large longitudinal excitation for vehicle active safety systems.
Abstract: Vehicle active safety systems stabilise the vehicle by controlling tyre forces. They work well only when the tyre forces commanded by the safety systems are within the friction limit. Therefore, knowledge of the tyre/road friction coefficient can improve the performance of vehicle active safety systems. This study presents four methods to estimate the friction coefficient based on four different excitation conditions: medium lateral excitation, large lateral excitation, small longitudinal excitation, and large longitudinal excitation. For the lateral excitation cases, the estimation is based on vehicle lateral/yaw dynamics and Brush tyre model, whereas for the longitudinal excitation cases, the estimation basis is the relationship between the tyre longitudinal slip and traction force. These four methods are then integrated to increase the working range of the estimator and to improve robustness. The performance of the integrated estimation algorithm is verified through experimental data collected on several surface conditions.
TL;DR: In this paper, the authors present an approach for assessing the accuracy of different frictional rolling contact theories, which takes a statistically oriented view and yields a better insight into the behaviour of the methods in diverse circumstances than is obtained when only a small number of (basic) circumstances are used in the comparison.
Abstract: This paper presents an approach for assessing the accuracy of different frictional rolling contact theories. The main characteristic of the approach is that it takes a statistically oriented view. This yields a better insight into the behaviour of the methods in diverse circumstances (varying contact patch ellipticities, mixed longitudinal, lateral and spin creepages) than is obtained when only a small number of (basic) circumstances are used in the comparison. The range of contact parameters that occur for realistic vehicles and tracks are assessed using simulations with the Vampire vehicle system dynamics (VSD) package. This shows that larger values for the spin creepage occur rather frequently. Based on this, our approach is applied to typical cases for which railway VSD packages are used. The results show that particularly the USETAB approach but also FASTSIM give considerably better results than the linear theory, Vermeulen–Johnson, Shen–Hedrick–Elkins and Polach methods, when compared with the ‘comp...
TL;DR: In this article, an autonomous obstacle avoidance system not only by braking but also by steering, as one of the active safety technologies to prevent traffic accidents, is proposed to prevent the vehicle from colliding with a moving obstacle like a pedestrian jumping out from the roadside.
Abstract: This study proposes an autonomous obstacle avoidance system not only by braking but also by steering, as one of the active safety technologies to prevent traffic accidents. The proposed system prevents the vehicle from colliding with a moving obstacle like a pedestrian jumping out from the roadside. In the proposed system, to avoid the predicted colliding position based on constant-velocity obstacle motion assumption, the avoidance trajectory is derived as connected two identical arcs. The system then controls the vehicle autonomously by the combined control of the braking and steering systems. In this paper, the proposed system is examined by real car experiments and its effectiveness is shown from the results of the experiments.
TL;DR: In this paper, a magneto-rheological (MR) damper-based semi-active controller for vehicle suspension is developed, which consists of a linear quadratic Gauss (LQG) controller as the system controller and an adaptive neuro-fuzzy inference system (ANFIS) inverse model as the damper controller.
Abstract: In this paper, a magneto-rheological (MR) damper-based semi-active controller for vehicle suspension is developed. This system consists of a linear quadratic Gauss (LQG) controller as the system controller and an adaptive neuro-fuzzy inference system (ANFIS) inverse model as the damper controller. First, a modified Bouc-Wen model is proposed to characterise the forward dynamic characteristics of the MR damper based on the experimental data. Then, an inverse MR damper model is built using ANFIS technique to determine the input current so as to gain the desired damping force. Finally, a quarter-car suspension model together with the MR damper is set up, and a semi-active controller composed of the LQG controller and the ANFIS inverse model is designed. Simulation results demonstrate that the desired force can be accurately tracked using the ANFIS technique and the semi-active controller can achieve competitive performance as that of active suspension.
TL;DR: In this article, a model of coupler angles has been added to normal longitudinal train simulation to allow comprehensive study of lateral components of couplers forces, and centripetal inertia calculations to determine quasi-static lateral forces and vertical forces.
Abstract: Lateral force components and impacts from couplers can adversely affect wagon stability. These issues are significant in longer and heavier trains increasing the risk of wagon rollover, wheel climb, wagon body pitch, bogie pitch and wagon lift-off. Modelling of coupler angles has been added to normal longitudinal train simulation to allow comprehensive study of lateral components of coupler forces. Lateral coupler forces are then combined with centripetal inertia calculations to determine quasi-static lateral forces, quasi-static vertical forces and quasi-static bogie lateral to vertical ratio, allowing the study of stringlining, buckling and wagon rollover risks. The approach taken allows for different rolling stock lengths, overhang and coupling lengths, and allows the study of angles occurring in transitions. Wagon body and bogie pitch are also studied with enhancements added to previous modelling to allow the study of wagon lift-off.
TL;DR: In this paper, a closed-loop dynamic simulation-based design method for articulated heavy vehicles (AHVs) with active trailer steering (ATS) systems is presented, which simultaneously optimises the active design variables of the controllers and passive design variables for the trailer in a single design loop (SDL).
Abstract: This paper presents a closed-loop dynamic simulation-based design method for articulated heavy vehicles (AHVs) with active trailer steering (ATS) systems. AHVs have poor manoeuvrability at low speeds and exhibit low lateral stability at high speeds. From the design point of view, there exists a trade-off relationship between AHVs’ manoeuvrability and stability. For example, fewer articulation points and longer wheelbases will improve high-speed lateral stability, but they will degrade low-speed manoeuvrability. To tackle this conflicting design problem, a systematic method is proposed for the design of AHVs with ATS systems. In order to evaluate vehicle performance measures under a well-defined testing manoeuvre, a driver model is introduced and it ‘drivers’ the vehicle model to follow a prescribed route at a given speed. Considering the interactions between the mechanical trailer and the ATS system, the proposed design method simultaneously optimises the active design variables of the controllers and passive design variables of the trailer in a single design loop (SDL). Through the design optimisation of an ATS system for an AHV with a truck and a drawbar trailer combination, this SDL method is compared against a published two design loop method. The benchmark investigation shows that the former can determine better trade-off design solutions than those derived by the latter. This SDL method provides an effective approach to automatically implement the design synthesis of AHVs with ATS systems.
TL;DR: In this paper, the influence of a stochastic spread (scatter) in traffic parameters on damage in the switch and crossing (S&C) is assessed, and it is concluded that the LHS-generated samples exhibit similar or smaller variance in damage compared with the randomly generated samples.
Abstract: Dynamic interaction between a railway freight vehicle and a switch and crossing (S&C) is studied by simulations of vehicle dynamics. In particular, the influence of a stochastic spread (scatter) in traffic parameters on damage in the S&C is assessed. The considered parameters are wheel profile and wheel-rail friction coefficient. To form a database for sampling, 120 wheel profiles from freight wagons in regular traffic have been measured and categorised with respect to wear. Among the investigated parameters, it is shown that equivalent conicity is the wheel profile parameter correlating best to damage in the S&C panels. The influence of hollow worn wheels on damage is also investigated, and it is found that such wheel profiles display a different running behaviour at the crossing transition. Convergence properties for samples of runs generated by Latin hypercube sampling (LHS) are compared with the corresponding properties obtained by pure random sampling. It is concluded that the LHS-generated samples exhibit similar or smaller variance in damage compared with the randomly generated samples.
TL;DR: In this article, an existing driver-vehicle model with neuromuscular dynamics is improved in the areas of cognitive delay, intrinsic muscle dynamics and alpha-gamma co-activation.
Abstract: An existing driver–vehicle model with neuromuscular dynamics is improved in the areas of cognitive delay, intrinsic muscle dynamics and alpha–gamma co-activation. The model is used to investigate the influence of steering torque feedback and neuromuscular dynamics on the vehicle response to lateral force disturbances. When steering torque feedback is present, it is found that the longitudinal position of the lateral disturbance has a significant influence on whether the driver’s reflex response reinforces or attenuates the effect of the disturbance. The response to angle and torque overlay inputs to the steering system is also investigated. The presence of the steering torque feedback reduced the disturbing effect of torque overlay and angle overlay inputs. Reflex action reduced the disturbing effect of a torque overlay input, but increased the disturbing effect of an angle overlay input. Experiments on a driving simulator showed that measured handwheel angle response to an angle overlay input was consist...
TL;DR: In this paper, the influence of a typical railway vehicle and track parameters on the level of ground vibrations induced in the neighbourhood is investigated, and it is shown that the vehicle has serious influence on the vibration level and should be considered in prediction models.
Abstract: A study is performed on the influence of some typical railway vehicle and track parameters on the level of ground vibrations induced in the neighbourhood. The results are obtained from a previously validated simulation framework considering in a first step the vehicle/track subsystem and, in a second step, the response of the soil to the forces resulting from the first analysis. The vehicle is reduced to a simple vertical 3-dof model, corresponding to the superposition of the wheelset, the bogie and the car body. The rail is modelled as a succession of beam elements elastically supported by the sleepers, lying themselves on a flexible foundation representing the ballast and the subgrade. The connection between the wheels and the rails is realised through a non-linear Hertzian contact. The soil motion is obtained from a finite/infinite element model. The investigated vehicle parameters are its type (urban, high speed, freight, etc.) and its speed. For the track, the rail flexural stiffness, the railpad stiffness, the spacing between sleepers and the rail and sleeper masses are considered. In all cases, the parameter value range is defined from a bibliographic browsing. At the end, the paper proposes a table summarising the influence of each studied parameter on three indicators: the vehicle acceleration, the rail velocity and the soil velocity. It namely turns out that the vehicle has a serious influence on the vibration level and should be considered in prediction models.
TL;DR: In this paper, a coordinated cascade control method with two sliding-mode variable structure controllers is presented, where the engine torque is tuned to achieve the maximum driving acceleration and then the active brake pressure is applied to the slipped wheel for further modification of the wheel slip ratio.
Abstract: Vehicle traction control system has been developed to enhance the traction capability and the direction stability of the driving wheels through the tyre slip ratio regulation. Under normal situations, if the tyre slip ratio exceeds a certain threshold, the slip ratio of the driving wheel is regulated by the coupled interaction of the engine torque and the active brake pressure. In order to obtain the best driving performance on a road under complicated friction conditions, the driving torque and the active brake pressure, need to be decoupled and adjusted to avoid penalisation of each other. In this paper, a coordinated cascade control method with two sliding-mode variable structure controllers is presented. In this control method, the driving wheel slip ratio is regulated by adjusting the engine torque and the wheel brake pressure. Through the sliding-mode controller, the engine torque is tuned to achieve the maximum driving acceleration and then the active brake pressure is applied to the slipped wheel for further modification of the wheel slip ratio. The advantage of this control method is that through proper regulation, the conflict between the two control inputs could be avoided. Finally, the simulation results validate the effectiveness of the proposed method.
TL;DR: In this article, a simplified analytic model of a motorcycle is developed by comparison to an extended multi-body model of the motorcycle, designed in Matlab/SimMechanics.
Abstract: The motorcycle lean (or roll) angle development is one of the main characteristics of motorcycle lateral dynamics. Control of motorcycle motions requires an accurate assessment of this quantity and for safety applications also the risk of sliding needs to be considered. Direct measurement of the roll angle and tyre slip is not available; therefore, a method of model-based estimation is developed to estimate the state of a motorcycle. This paper investigates the feasibility of such a motorcycle state estimator (MCSE). A simplified analytic model of a motorcycle is developed by comparison to an extended multi-body model of the motorcycle, designed in Matlab/SimMechanics. The analytic model is used inside an extended Kalman filter. Experimental results of an instrumented Yamaha FJR1300 motorcycle show that the MCSE is a feasible concept for obtaining signals related to the lateral dynamics of the motorcycle.
TL;DR: In this article, a coupled vehicle/track dynamic model considering the earthquake effect is developed, where the vehicle is modelled as a multi-body system of 35 degrees of freedom and the nonlinear suspension characteristic is considered.
Abstract: In order to investigate the mechanism of derailment of high-speed trains due to an earthquake, a coupled vehicle/track dynamic model considering the earthquake effect is developed. The vehicle is modelled as a multi-body system of 35 degrees of freedom and the nonlinear suspension characteristic is considered. The slab track model considers the deformable rails, the discrete support of fasteners and the deformable slabs. Rails are assumed to be Timoshenko beams supported by the rail fasteners discretely, and the slabs are modelled with solid finite elements. The coupling of the vehicle and the track considers the track moving with respect to the vehicle running at a constant speed, and such a coupling model can simulate the effect of the periodical discrete rail supports on the vehicle/track interaction. The least-square curve fitting (LSCF) approach is introduced to integrate the originally recorded earthquake acceleration to acquire the velocity and displacement-time series of the earthquake. The system motion equations are solved by means of an explicit integration method in the time domain. The present paper analyses in detail the effect of the earthquake characteristic on dynamical behaviour of the vehicle and the track and the transient derailment criteria. The considered derailment criteria include the ratio of the wheel/rail lateral force to the vertical force, the wheel loading reduction, and the wheel/rail contact point traces on the wheel tread and the wheel rise with respect to the rail top, respectively. The present investigation includes the effect of lateral earthquake motion, vertical earthquake motion, operation speed, and their combined effect on the existing derailment criteria, respectively.
TL;DR: In this article, the steering torque control of a rack-assisted electric power steering (EPS) is described, and an H∞-controller is designed, implemented and compared with other steering torque controllers.
Abstract: Electric power steering (EPS) is more and more in use for passenger cars. Compared with hydraulic steering systems there are many advantages, such as reduced CO2 emissions and the possibility to use the EPS motor torque for advanced driver assistance systems. One task of the steering system is to give the driver an adequate steering feel. This includes providing road feedback and the right level of assistance torque. This article describes the steering torque control of a rack-assisted EPS. The controller's task is to follow a reference steering torque quickly and accurately. First, a mechanical model of the EPS is shown. Then, an H∞-controller is designed, implemented and compared with other steering torque controllers. As steering torque discontinuities are a topic when looking at new control algorithms, the phenomenon and its cause are analysed using a detailed mechanical model. The results of this analysis are considered in the controller design.
TL;DR: In this paper, the bifurcation analysis of a rather simple model describing an automobile negotiating a curve is presented. And the results are cross-validated by exploiting handling diagram theory.
Abstract: The paper deals with the bifurcation analysis of a rather simple model describing an automobile negotiating a curve. The mechanical model has two degrees of freedom and the related equations of motion contain the nonlinear tyre characteristics. Bifurcation analysis is adopted as the proper procedure for analysing steady-state cornering. Two independent parameters referring to running conditions, namely steering angle and speed, are varied. Ten different combinations of front and rear tyre characteristics (featuring understeer or oversteer automobiles) are considered for the bifurcation analysis. Many different dynamical behaviours of the model are obtained by slightly varying the parameters describing the tyre characteristics. Both simple and extremely complex bifurcations may occur. Homoclinic bifurcations, stable and unstable limit cycles (of considerable amplitude) are found, giving a sound and ultimate interpretation to some actual (rare but very dangerous) dynamic behaviours of automobiles, as reported by professional drivers. The presented results are cross-validated by exploiting handling diagram theory. The knowledge of the derived set of bifurcations is dramatically important to fully understand the actual vehicle yaw motions occurring while running on an even surface. Such a knowledge is a pre-requisite for robustly designing the chassis and for enhancing the active safety of vehicles.
TL;DR: In this paper, a nominal control design algorithm for rollover prevention of heavy articulated vehicles with active anti-roll-bar control is presented, based on an extension of linear quadratic regulator control for state derivative-induced output regulation problems.
Abstract: This paper presents the application of a nominal control design algorithm for rollover prevention of heavy articulated vehicles with active anti-roll-bar control. This proposed methodology is based on an extension of linear quadratic regulator control for ‘state derivative-induced (control coupled) output regulation’ problems. For heavy articulated vehicles with multiple axles, a performance index with multiple rollover indices is proposed. The proposed methodology allows us to compare the usefulness of various control configurations (i.e. actuators at different axles of the vehicle) based on the interaction of this control configuration with vehicle dynamics. Application of this methodology to a specific heavy articulated vehicle with a tractor semi-trailer shows that a single active anti-roll-bar system at the trailer unit gives better performance than multiple-axle actuators at tractor and trailer together with the single lane change manoeuvre as the external disturbance. Thus, the proposed methodology...
TL;DR: In this paper, a curving adaptive cruise control (ACC) system that is coordinated with a direct yawmoment control (DYC) system and gives consideration to both longitudinal car-following capability and lateral stability on curved roads is presented.
Abstract: The paper presents a curving adaptive cruise control (ACC) system that is coordinated with a direct yaw-moment control (DYC) system and gives consideration to both longitudinal car-following capability and lateral stability on curved roads. A model including vehicle longitudinal and lateral dynamics is built first, which is as discrete as the predictive model of the system controller. Then, a cost function is determined to reflect the contradictions between vehicle longitudinal and lateral dynamics. Meanwhile, some I/O constraints are formulated with a driver permissible longitudinal car-following range and the road adhesion condition. After that, desired longitudinal acceleration and desired yaw moment are obtained by a linear matrix inequality based robust constrained state feedback method. Finally, driver-in-the-loop tests on a driving simulator are conducted and the results show that the developed control system provides significant benefits in weakening the impact of DYC on ACC longitudinal car-following capability while also improving lateral stability.
TL;DR: In this article, a new hydraulically interconnected suspension (HIS) system is proposed for the implementation of a resistance control for the pitch and bounce modes of tri-axle heavy trucks.
Abstract: In this paper, a new hydraulically interconnected suspension (HIS) system is proposed for the implementation of a resistance control for the pitch and bounce modes of tri-axle heavy trucks. A lumped-mass half-truck model is established using the free-body diagram method. The equations of motion of a mechanical and hydraulic coupled system are developed by incorporating the hydraulic strut forces into the mechanical subsystem as externally applied forces. The transfer matrix method (TMM) is used to evaluate the impedance matrix of the hydraulic subsystem consisting of models of fluid pipes, damper valves, accumulators, and three-way junctions. The TMM is further applied to find the quantitative relationships between the hydraulic strut forces and boundary flow of the mechanical–fluid interactive subsystem. The modal analysis method is employed to perform the vibration analysis between the trucks with the conventional suspension and the proposed HIS. Comparison analysis focuses on free vibration with identi...
TL;DR: In this paper, a new methodology to design the vehicle GCC (global chassis control) nonlinear controller is developed, where the vehicle is treated as a mechanical system of two-rigid-bodies which has 6 DOF (degree of freedom), including longitudinal, lateral, yaw, vertical, roll and pitch dynamics.
Abstract: A new methodology to design the vehicle GCC (global chassis control) nonlinear controller is developed in this paper. Firstly, to handle the nonlinear coupling between sprung and unsprung masses, the vehicle is treated as a mechanical system of two-rigid-bodies which has 6 DOF (degree of freedom), including longitudinal, lateral, yaw, vertical, roll and pitch dynamics. The system equation is built in the yaw frame based on Lagrange's method, and it has been proved that the derived system remains the important physical properties of the general mechanical system. Then the GCC design problem is formulated as the trajectory tracking problem for a cascade system, with a Lagrange's system interconnecting with a linear system. The nonlinear robust control design problem of this cascade interconnected system is divided into two H ∞ control problems with respect to the two sub-systems. The parameter uncertainties in the system are tackled by adaptive theory, while the external uncertainties and disturbances are d...
TL;DR: In this paper, a three-dimensional nonlinear rigid body model has been developed for the investigation of the crashworthiness of a passenger train using the multibody dynamics approach, and the crash scenario is limited to the train colliding on to a fixed barrier symmetrically.
Abstract: In this paper, a three-dimensional nonlinear rigid body model has been developed for the investigation of the crashworthiness of a passenger train using the multibody dynamics approach. This model refers to a typical design of passenger cars and train constructs commonly used in Australia. The high-energy and low-energy crush zones of the cars and the train constructs are assumed and the data are explicitly provided in the paper. The crash scenario is limited to the train colliding on to a fixed barrier symmetrically. The simulations of a single car show that this initial design is only applicable for the crash speed of 35 km/h or lower. For higher speeds (e.g. 140 km/h), the crush lengths or crush forces or both the crush zone elements will have to be enlarged. It is generally better to increase the crush length than the crush force in order to retain the low levels of the longitudinal deceleration of the passenger cars.
TL;DR: A description of the client interface in Simulink for co-simulation with Gensys is proposed and the evolution of the proposed approach has been performed by means of a simulation of a simplified traction control system for a hauling locomotive running on straight track conditions.
Abstract: The design of mechatronic systems for rail vehicles requires the implementation of modern software tools. Nowadays, it is common to use co-simulation for the creation of mechatronic models. This approach is usually based on the combination of two types of software – multi-body simulation packages for mechanical models and tools for simulation of electric, control systems, etc. The existing commercial codes (SIMPACK, VI-RAIL, VAMPIRE, UM) provide different approaches for co-simulation; however, they have a lot in common. The one thing that makes them very similar is the use of Simulink for co-simulation. In this paper, we propose a description of the client interface in Simulink for co-simulation with Gensys. The evolution of the proposed approach has been performed by means of a simulation of a simplified traction control system for a hauling locomotive running on straight track conditions.